Slice the salmon, zucchini and red onion into cubes wide enough that they will securely hold on the skewer. Set aside.
In a medium size mixing bowl combine all of the marinade ingredients and whisk until combined.
Add the salmon to the marinade and chill for 30 minutes.
Toss the zucchini and red onion in the corn oil, dill, salt and pepper.
If using wooden skewers soak in water for 10 minutes. If using metal skewers lightly spray with cooking oil so the ingredients do not stick.
Remove the salmon from marinade and thread the salmon, zucchini and red onion on the skewers.
Grill 4 minutes on each side.
When flipping or removing the skewers use tongs to grab the skewer itself or a slice of zucchini. If you try to move the skewers by grabbing the salmon it will flake off.